N Project: 4" Glass Fibre/Carbon Fibre Rocket, Part 3

Top photo: Professor Eugene Trubowitz is examining one of the fresh arrived Rocketman parachutes at the machine shop of the Swiss Federal Institute of Technology in Zurich, Switzerland, in late summer of 2000. All three rockets of the N project used Rocketman main und drogue parachutes.

Second photo from top: the two custom threaded forward closures of the Dr. Rocket 98 mm aluminium motor cases used for the two 4" rockets of the project. We were very fortunate to be granted to use the tool machines of the Institute for any such special modifications required in the course of our project.

Lower two photos: first trail assembly of the electronics compartment for the 4" glass fibre/carbon fibre rocket. The design of the electronics compartments for both 4" rockets was identical. The mounting base for the electronics thus consisted of an aluminium ring/shoulder, screwed to the modified forward closure. This arrangement further provided a mounting point for the glass upper airframe section.

The circular white insulation foam disc was intended to shield the electronics from the head emitted by the subjacent N2000 composite motor. Again, four threaded steel rods served to hold four custom- made aluminium mounting bridges, to which the two BlackSky AltAcc dual deployment recording accelerometers would subsequently be attached.

N Project: 4" Glass Fibre/Carbon Fibre Rocket, Part 2

Further images depicting the construction of the 4" glass fibre/carbon fibre N-motor rocket built for the BALLS 10 experimental launch held at Black Rock Desert in Nevada, in 2000. Top photo shows the custom made carbon fibre 4" nose cone with glass shoulder and steel tip. This beautifully immaculate cone was manufactured by Swiss Composite, based on calculations by Professor Eugene Trubowitz.

Centre photo shows Professor Trubowitz working on the rocket while we were performing a first trial assembly of the full (but still incomplete and unpainted) vehicle at the machine shop of the Swiss Federal Institute of Technology in Zurich, Switzerland. Components of the other two rockets of the N project can be seen to the right: the red and silver 4" aluminium/glass fibre/carbon fibre rocket with its welded aluminium fins and, at lower right, a section of the carbon fibre fin can of the 6" glass fibre/carbon fibre rocket.

Lower photo shows the 4" glass fibre/carbon fibre N-motor rocket erected vertically for the first time, in mid-September of 2000. The red Dr. Rocket N2000 98 mm aluminium motor case can be faintly seen through the lower glass fibre airframe section. The steel tip of the nose cone is provisionally held in place by masking tape; it would later be secured internally by means of threaded steel rod.

Vehicle 79 (Redux)

Vehicle 79 Dominator III ranks among my favourite rockets in my fleet. It is an uncomplicated rocket to fly, and its simple design provides a consistently impressive performance on F and G composite motors. Vehicle 79 was constructed from a variety of US Rockets and Aerotech components, featuring through-the-wall plywood fins, a custom-made aluminium baffle unit, and a payload section with a length of 315 mm. Top photo was taken at my former workshop in Thalwil, Switzerland, on November 22, 2010.

Lower photo shows Vehicle 79 on a friend's aluminium launch pad, on the occasion of our "last launch of the century", held on December 22, 1999, in northeast Switzerland. We flew our rockets from 2 to 5:30 pm; the temperature fluctuated around the freezing point. This was our seventh flight that day and thus our last flight of the launch and of the century. Vehicle 79 was powered by an Aerotech 29mm F20-7W Econojet motor. The payload flown consisted of a Missile Works RRC2 altimeter and a custom 9V piezo sonic locator. The flight was perfect and loud, and the RRC2 indicated an altitude of 1274 ft.

1972 Enerjet Catalogue

Sample pages from the unique and intriguing 1972 Enerjet advanced rocketry model products catalogue (no. 721).

As deeply curious and utterly determined teenagers building model rockets in remote (from a consumer point of view) Switzerland in the mid to late 1970s, we were continuously driven towards increasingly advanced rocket concepts and the quest for rocket motors more powerful than the commonly available A, B, C, and D-class motors. Mind you, it was far from granted to find even such "regular" motors in Switzerland at the time. Our ambitions were satisfied to some extent when a German distributor brought the product line of Flight Systems Inc. to our hemisphere and we were finally able to obtain their range of D, E, and F black powder motors.

In our minds, however, Enerjet represented the holy grail of advanced model rocketry, and it therefore served as the underlying inspiration for many of our own projects. This was of course long before readily available information by means of the internet, and even though Enerjet was no longer trading as an active company by that time, the company, for us, was thus an entity equally shrouded in mystery and emitting a limitless fascination. The few things we knew about Enerjet had been glanced from pictures in books (the Handbook Of Model Rocketry) and Centuri brochures, or from the remnants of Enerjet's existence as evident in Centuri's catalogues.

I would have given anything to own the 1972 Enerjet catalogue at the time (or to even be granted to have a brief look at it), but any such publications remained unobtainably elusive for us two rocket obsessed adolescents in Switzerland. Only much later in my life was I finally able to obtain a pristine original edition. The infinite waiting period mattered little; Enerjet's very existence and iconic designs still represent the same captivating inspiration to me to this very day.

The above excerpts from the 24-page catalogue show, for example, Enerjet's revolutionary "port burning" composite motors with glass fibre casing, or the fantastic (and operable) Nike Smoke semi scale rocket (vaguely similar to the Centuri kit) and Nike Ram high altitude payload rocket.

1972 Enerjet catalogue sample pages © by Enerjet Inc., Phoenix/AZ, USA, 1972, scanned from my personal copy of the catalogue.

[Entry amended October 31, 2016; with thanks to Chris Michielssen.]

N Project: 4" Glass Fibre/Carbon Fibre Rocket, Part 1

Construction of the 4" glass fibre/carbon fibre N-motor rocket, the final of three flight vehicle designs built by our team for the BALLS 10 experimental launch held at Black Rock Desert in Nevada, in 2000. All three rockets were designed by the project's initiator, Swiss Federal Institute of Technology Professor Eugene Trubowitz, who subsequently invited me to be a main partner in logistics, financing, construction, and launch.

Powered by an Aerotech N2000 motor held in a Dr. Rocket 98 mm aluminium N motor case, this 4" rocket was to comprise glass fibre lower and upper airframe sections, three carbon fibre fins, and a custom-made carbon fibre and steel nose cone. The rocket's design resulted in a length of 2336 mm and a diameter of 101 mm.

Top photo shows the very early stages of the rocket's construction at Professor Trubowitz' home, in July of 2000. The carbon fibre fins have been aligned and attached to the lower airframe section with epoxy adhesive.

The next step, undertaken at the machine shop of the Swiss Federal Institute of Technology in Zurich, involved preparing a mould for the manufacture of laminated fillet strips. Centre photo shows these laminated fillets after attachment to the fin/airframe joint, in August 2000. One such laminated, formed fillet can be seen bottom left.

Lower photo shows Professor Trubowitz inspecting the provisional placement of the custom-made aluminium rail guide stand-off. The unfinished rocket in the foreground is the 4" aluminium/glass fibre/carbon fibre N-motor vehicle previously detailed on this blog.

Vehicle 77 Redux

A clear personal favourite in my fleet, the Enerjet Nike Ram-inspired Vehicle 77, photographed in northeast Switzerland on July 30, 1999, on the occasion of a flight powered by a 24 mm Aerotech E28-7T RMS composite motor. This flight took place in the early afternoon of a beautifully clear day, with low winds, and a temperature of around 30 degrees Celsius.

Launched off an Aerotech Mantis pad, Vehicle 77 carried a 6 volt piezo sonic locator. The rocket flew fast, very stable, and out of sight, to a computed altitude of slightly over 800 meters. The parachute deployed perfectly, but the rocket's payload section and parachute became entangled in a barn drain pipe upon landing. The tallest member of our little launch group was just able to pull it free, but the piezo sonic locator was lost during the retrieval, and the plastic parachute was damaged. Vehicle 77 itself survived in perfect condition.

A few weeks later, I replaced damaged parachute (it had likely been the wrong choice for such a rocket at any rate) with a nylon parachute by Rogue Aerospace.

Rocket Fleet, 1989

Scans of two regrettably very deficient analog photos taken at my former home in Nürensdorf, Switzerland, in autumn of 1989, depicting part of what was then my rocket fleet as well as some designs under construction at the time.

Top photo shows, from left: Vehicle 59, built from Flight Systems and Centuri parts and designed to fly with Flight Systems E black powder motors. Vehicle 59 measured 886 mm in length (including a payload section of 456 mm length). The rocket in the center is my scratch-built Honest John semi scale model (still lacking any finer details), while the model on the right is Vehicle 51 B Enigma II, a development of the earlier Vehicle 39 A Enigma. Vehicle 51 B was constructed using Estes, Centuri, and CMR components and intended to be flown with Flight Systems E and F motors. It measured 896 mm in length and featured a payload section of 158 mm usable space. The lower and upper sections of the rocket were recovered by means of two separate parachutes.

Lower photo, from left: Vehicle 32, a cluster design utilizing three 18 mm motors and featuring a payload section. Next to it are Vehicle 23, a 24 mm experimental design with ultra thin, high aspect-ratio plywood fins, and Vehicle 22 B, also using three high aspect-ratio plywood fins that were strengthened with an epoxy coating. The rocket line-up is completed by Vehicle 48 A Heracles (designed for 21 mm and 24 mm D motors), Vehicle 39 A Enigma, and Vehicle 44 A Rhea (a sport model with payload section, built specifically for Flight Systems D18 motors).

Homage To Model Missiles, Inc.

I scratch-built this semi scale Aerojet-General Aerobee-Hi in 1986, using Centuri parts. It was an homage of sorts to the beginnings of our hobby and thus to some of the protagonists that had inspired me during my youth, ten years earlier: Orville H. Carlisle and G. Harry Stine.

As described, for example, in a fantastic article titled The First Model Rocket Kits, authored by G. Harry Stine and published on pages 5 to 9 of the February 1978 issue of Model Rocketeer magazine, Carlisle and Stine's Model Missiles, Inc. produced the Aerobee-Hi as the company's first proper model rocket kit in 1958. Moreover, I also admired the early Aerobee-Hi model rockets when I obtained what was my first copy of the Handbook Of Model Rocketry (Fourth Edition) in 1976 or 1977, such as in the formidable launch photo on page 125. We were model rocket obsessed teenagers at the time and not only glorified G. Harry Stine but also the beautifully pure design of the Aerobee-Hi rocket.

My own Aerobee-Hi was first launched on May 28, 1999, many years after I had originally completed it. The top photo shows the final preparations for this maiden flight, conducted with an Estes B6-4 motor in northeast Switzerland. As can be expected for such an immaculate design, it performed flawlessly. The lower two photos show the same rocket in May 2016, in Zurich, Switzerland.